This invention relates to cable connectors of the rotatable-jaw, clamping type. Such connectors, having relatively rotatable jaws with alignable bores therein adapted to receive the end of a cable, which is then securely clamped between the jaws when they are rotated to a closed position, have become well known in the art. A basic design for such a connector is disclosed in U.S. Pat. No. 3,118,720. As shown therein, such a clamp comprises, in general, a female member having a C-shaped sleeve and a male member having a cylindrical head for relative rotatable movement within the sleeve. The sleeve and head have respective diametrical bores which, in the open position of the connector, are axially aligned to receive a cable (such as an electrical conductor). The male and female members have tails which, when secured together, cause the internal surfaces of the bores to exert clamping forces on the cable. The connector is adapted to be mounted upon same supporting structure, such as a terminal strip in a panel box.
Such connectors are especially useful in the electrical industry, and are being commercialized; one of their particular advantages is their suitability for use with stranded aluminum electrical cables. As a result of their promising commercial potential, they have been the subject of much development and improvement, as is evidenced for example by U.S. Pat. Nos. 3,138,422; 3,351,889; 3,406,372; 3,801,952; 3,831,134; 3,861,771; 3,879,104; 3,883,211; 3,980,381; 3,990,129; 4,001,921; 4,014,078; and 4,126,918. Among the important improvements disclosed in these patents are, for example, X-shaped bores to reduce shearing in U.S. Pat. No. 3,406,372; locking means in U.S. Pat. No. 3,801,952; and size-adjustability in U.S. Pat. No. 4,126,918.
Despite this fairly crowded art reflective of intensive development activity, however, the basic design of such connectors has remained virtually unchanged. The female member is generally C-shaped, with a mounting tail attached to one leg of the C, and with cable-receiving openings or bores through both legs of the C. The male member has a cylindrical head with a diametrical cable-receiving bore, and a mounting tail tangentially attached to the head. The male head is adapted to fit within the C-portion of the female member and the two members are relatively rotatable. In the open position of the connector, the male and female tails are spaced apart, and the male and female bores are in general axial registry to receive a cable. When the cable is inserted, the tails are forced together, and the female member rotates on the male member. This causes clamping forces to be exerted on the cable as follows: At the front end of the connector (that is, the end of the connector at which the cable is inserted; usually through the bore in the free leg of the female C), the lower interior surface of the front female bore presses up against the cable, while the upper interior surface of the front part of the male bore presses down against the cable; similarly, at the rear end of the connector, the upper interior surface of the rear female bore presses down against the cable, while the lower interior surface of the rear part of the male bore presses up against the cable. This results in clamping of the cable by four pressure points: one opposed pair of pressure points at the front of the connector and one opposed pair at the rear. The clamping is completed by securing the tails together, usually by a bolt through registering apertures in the tails; the bolt also serves to mount the connector to the supporting structure.
The locking mechanism disclosed for example in U.S. Pat. No. 3,801,952 permits the connector to be locked in closed or nearly-closed position to hold the cable in place while the clamping is completed--i.e., while the mounting bolt is tightened down. The size-adjustability feature disclosed in U.S. Pat. No. 4,126,918 contemplates some means for altering the cable-clamping or receiving capability of the connector, so that it can accommodate cables of different sizes, by altering the spatial relationship of the axes of the male and female bores. Both of these features are very desirable in commercial devices.
One common feature in these prior art connectors is the relative configuration of the male and female members. The male member is adapted to be mounted directly against the supporting structure, and thus its tail is the lowermost element of the connector. Thus, although rotation between the two members is always properly viewed as being "relative", for practical purposes it is the female member which rotates upon the male member. This dictates the general configuration of the female member: the open portion of the C is directed generally downwardly toward the supporting structure so that there will be clearance between the C legs for rotation. Although at least one prior patent (U.S. Pat. No. 3,351,889; FIG. 10) does contain an incidential disclosure of a connector in which the male member might be said to rotate within the female member, this disclosure relates to a very specialized type of connector having insulation-piercing jaws for covered wire; moreover, the wire-receiving openings in the female member are again through the legs of the C, and the wire consequently enters the connector from the top. By and large, the prior art connectors disclosed in the listed patents disclose the same male-female configuration in which the male member is asymmetrical, so that its tail can be mounted directly against the supporting structure, and in which the open portion of the C-shaped sleeve in the female member is directed downwardly for clearance in rotation.